With constant development of thin film transistor liquid crystal display (TFT-LCD), user's requirements for a narrow bezel of a display are getting higher and higher. To further reduce a width of the display bezel, currently a Gate-On-Array (GOA) circuit is generally fabricated on a TFT substrate in the industry. In this way, a gate electrode driving chip (IC) becomes not only unnecessary, but also a very narrow bezel can be realized. The display bezel using a gate electrode driving chip IC is generally 5 mm or more, and the display bezel for the TFT substrate driven by the GOA circuit is generally less than 3 mm.
The structure of the TFT display panel driven by the GOA circuit may be shown in FIG. 1, in which a TFT substrate 1 is provided on a bottommost layer, on which a signal line driving chip IC is pressure welded, a color filter (CF) substrate 2 is provided on a topmost layer, with a liquid crystal layer interposed therebetween (not shown in FIG. 1). A solid-line box AA indicates an effective display region; the TFT substrate 1 and the CF substrate 2 are attached together with a layer of sealant 11 interposed between them to prevent leakage of the internal liquid crystal; there are two sets of GOA circuits 12 within the region enclosed by the sealant 11, and the two sets of GOA circuit 12 are symmetrically disposed on both sides of the AA region, for progressive scanning the gate lines in the display region; in order to further reduce a bezel width of the display panel, as shown in FIG. 1, a distance between the sealant 11 and an edge of the panel and a distance between the sealant 11 and the GOA circuit 12 are usually small.
For a display panel of active-matrix driving type, there is provided a conductive ITO thin film on the surface of CF substrate, which surface is close to the liquid crystal layer, as a common electrode; and the common electrode and a pixel electrode on the surface of the TFT substrate constitute an electric field structure, to drive the liquid crystal between the two substrates to deflect. It should be specially noted that, charges of the common electrode on the CF substrate are usually derived from the charges on the TFT substrate that are transferred via conductive particles within the sealant. However, there are some gate lines connected with data lines in the GOA circuit structure, and the cross-sectional view thereof is shown in FIG. 2, in which 21 indicates a gate line layer metal, 22 indicates a gate insulating layer, 23 indicates a semiconductor layer, 24 indicates a data line layer metal, 25 indicates a passivation layer, and 26 indicates a pixel electrode ITO layer; and a via-hole H1 connects the pixel electrode ITO layer 26 with the data line layer metal 24, a via-hole H2 connects the pixel electrode ITO layer 26 with the gate line layer metal 21, so as to implement connection between the gate line layer metal 21 and the data line layer metal 24. Because there are provided some such via-holes within the TN-type liquid crystal display panel GOA circuits, the sealant which binds the TFT substrate and the CF substrate together must be isolated from the GOA circuits, otherwise the conductive particles within the sealant will make all the ITO layers in the GOA short-circuited via the common electrode ITO on the CF substrate, as shown in FIG. 3. In the fabrication process of a narrow-bezel display panel of TN type, since a distance between the sealant and the GOA circuit is too small, it is difficult to completely isolate the sealant from the GOA circuit in the traditional design, making it difficult to avoid electrode short-circuit, which affects display effect of the display panel, and severely restricts narrow-bezel design for the TN-type display panel.